Summary of Significant Accounting Policies - Product Warranty Liability (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Jan. 31, 2015	Apr. 30, 2016	Apr. 30, 2015	Oct. 31, 2015	Oct. 31, 2014
Product Liability Contingency [Line Items]
Product Warranty Accrual	$ 907	$ 1,059		$ 907	$ 1,059	$ 994	$ 1,197
Product Warranty Accrual, Warranties Issued				69	116
Product Warranty Accrual, Currency Translation, Increase (Decrease)				1	(5)
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties(A)(B)				51	(39)
Extended Warranty Program:
Product Warranty Accrual, Payments				(208)	(210)
Product Warranty Accrual, Current	429	496		429	496
Product Warranty Accrual, Noncurrent	478	563		478	563
Extended Warranty Programs [Member]
Extended Warranty Program:
Deferred Revenue, Revenue Recognized	38	$ 38		76	$ 75
Deferred Revenue	367			$ 367		$ 401
Product Warranty Accrual [Member]
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Adjustments to pre-existing warranties(A)(B)	$ 46		$ (57)
Product Warranty Accrual, Preexisting Increase Decrease Per Share, Net of Tax	$ 0.56		$ (0.70)